I did this once, but now I can't find it again. Can someone point the way?

I'm not positive, but go to your profile, go to change your public profile, then scroll down to "brief message to show at the bottom of your posts." I think that may do it.

I agree; what she said!!

Found it. Thanks!

I was hoping to be able to add a signature above that area, right below the message. Is this an option? Hi Liz.

The repeated signature is below the line, where you have your name. (any reason you repeated it?
It's already in your name section above your location) Anything above that line is the space for your post.